Night of Nights
by Qu0thTheRavenNeverm0re
Summary: Gwen is a mediocre citizen of the Nightosphere until a mysterious portal whisks her to the Land of Ooo. As you would expect, she meets our favorite adventurers and explores the world beyond the chaos she had grown used to. But evil lurks beneath- there's a reason Gwen was able to leave the Nightosphere, and it just might endanger everyone Finn holds dear. Not too much shipping
1. Chapter 1

**Am I seriously about to write an Adventure Time fanfic? Oh jeezus, I've just taken my weirdness to a new level. I can't stop thinking of the Ice King being all, "So whaddaya guys think about the fan fiction I wrote about you?". Oh well, at least it's better than a Justin Bieber fan fiction. Seriously, who READS that kind of... glub?**

**Anyways, thanks for reading, I hope you like it. It was harder than I thought to make a Nightosphere character because they're supposed to be average Joes and sheeple and such, but they also live in a realm of chaos and violence. Then there's always the risk of making a Mary Sue. If you want to offer any criticism, I'd be grateful, especially if it has to do with characterization. **

**Here's a link to a picture of the N****ightosphere (I'm sorry you have to take all the spaces out, but if I don't put them in it will be marked as spam):**

**h t t p : / / i m a g e s 1 . w i k i a . n o c o o k i e . n e t / _ _ c b 2 0 1 2 0 5 2 6 2 3 0 0 4 7 / a d v e n t u r e t i m e w i t h f i n n a n d j a k e / i m a g e s / 8 / 8 1 / E x t e r i o r - N i g h t o s p h e r e P a n . j p g**

Gwen woke up to the sound of an even rhythm pounding below her, as well as a gentle rocking of the surface she lay on. With a start, she jerked herself to her knees and looked around before realizing she had fallen asleep on the back of a Half- Monster demon.

Sighing in relief, she leaned back onto her hands and surveyed the scene around her. It was just an ordinary day in the Nightosphere- fire, stone ruins, demons scattered here and there. The sky was a menacing violet today, she noted, which made the bright orange flames stand out brilliantly. Her eyes scoured the landscape for anything interesting. Seeing nothing, Gwen sank down onto her back again and closed her eyes.

She thought of how she used to travel inside demons like these when her dad was still around, when they used to go scavenging together. He showed her the best places to find food, like deep down underneath abandoned buildings in forgotten cellars, or in cliffside crevices where no one looked. He explained the rules to her that every demon should know: stick to the systems and follow the crowd. When he had been disintegrated by one of Hunson Abadeer's clouds, she hadn't dwelled too much on his death. After all, everyone in the Nightosphere fended for himself. Many demons didn't have any parents around to teach them the rules- if you did, you were lucky, and if you didn't, you figured them out yourself. By that time, she knew what you needed to know. But still, it was nice to remember the time when there was someone else with her.

There had been other demons from time to time that had been her companion. Usually it was when you wanted something that you found someone to help you. But you never stayed long with a group, unless you joined a cult like the Midnight Circle. That was just how it worked.

Gwen realized that she couldn't remain on the Half- Demon's back forever.

"Hey, you wanna let me down here?" she called to it. He knelt knelt down. "Thanks."

The creature got up and sped away. Immediately, Gwen leaped under the threshold of a building to avoid being crushed by the foot of a giant Tarantula Demon. You had to be wary when you lived down here. She waited until it was gone before cautiously venturing back out.

She jumped down the stacked ledges that formed the different floors of the building until she stood on the ground. Gwen navigated carefully around pillars of flame until she came to a strange bridge made of twisting red tendrils. Normally, one would turn a blind eye to them as nothing but supports, but it was common knowledge down here that one could scrounge a tasty breakfast from the strange vines.

Gwen climbed underneath the bridge to where the tendrils formed a tangle of branches that held up the pathway of the bridge. Underneath the thick limbs of plant grew a number of purplish apples. Only agile climbers could reach them, but sometimes peddlers traded them to the demons whose legs were too stubby to reach them. Gwen swung to them and plucked three off of the vine. She bit into one of them with a satisfied crunch. The other two she stuffed in the pocket of her red burlap sack dress for later.

"Hey! You can't go down there! That's restricted property!" Gwen heard a voice say. Alarmed, she jumped up to run until she realized it wasn't directed at her.

She ducked in between two tendrils so as not to be seen. The voice had come from a tall demon with three eyes and two horns that stuck out the sides of his head. He was outfitted with a quiver of broken arrows and a bow that was much too small for him.

"Since when are you in charge of what I do?" said another voice, which must've belonged to whoever the first demon was addressing. It climbed back up onto the bridge, and Gwen got a glimpse of a squat little four-legged demon. She chuckled to herself. Everyone knew that you can't climb with four legs. Even you tried, you would be too slow and get caught, or else not be able to pick the fruit. No one must have told _him_ that, she supposed.

"I'm the policeman!" said the first demon. "I'm supposed to tell people what to do!"

"Who said you were the policeman?" the short demon yelled angrily.

The tall demon started to respond, but having no answer, the four-legged demon took off with a gleeful laugh. The policeman started after him, but just then, both were devoured by a huge mouth- worm.

Gwen laughed and hoisted herself back up onto the bridge. Kicking a couple smaller demons out of the way, she grabbed onto the tail of a giant bat that was flying overhead and held on tight. The bat soared over the sea of lava and a couple of small cities. She saw a long line of hooded figures traveling swiftly towards their temple atop a hill, one of the only well-kept buildings in the Nightosphere. The Midnight Circle, she presumed. Today must have been one of their ceremonial days, because one by one, the figures ascended the stairs, entered the temple, and pitched themselves off the steep ledge on the other side. Even though it was blatantly suicide, the order of it seemed out of place among everything else.

Just then, something strange caught her eye. Something seemed to have appeared down in one of the cities. She let go of the bat and landed a few yards below the thing she had seen. Gwen looked around. No one else seemed to have noticed it. She scrambled up the stone to reach it.

The thing glowed at she stepped apprehensively towards it. It looked to be some sort of light vortex. Gwen noticed that it was blue. That was odd... most things in the Nightosphere were red or black or violet. The vortex gave off a faint hum, as if the energy inside of it was stirring. The light seemed to swirl around itself. The edges crackled oddly with heat.

Her footsteps echoed on the concrete. It felt like the rest of the world had been put on pause, and now it was just her and the vortex. It felt like it was drawing her towards it with its intense blue energy. She didn't know if she would be able to turn away from it, even if she wanted to. But it wasn't as if she wanted to. She reached out her hand and touched it.

Instantly she was pulled into the vortex. A strong wind forced her down a tunnel of bright blue light. She felt hot electricity coursing through the swirls of blue and in the air around. Everything was spinning like a cyclone, and she feared she would pass out. The energy became more and more intense as her vision grew more and more faint...

Suddenly, everything stopped. Gwen found herself sprawled on solid ground. Around her, everything was bright- brighter than the Nightosphere, at least. She blinked.

In front of her was a very strange group of people. They sat absolutely still, their mouths frozen open. Gwen realized she must look the same way. One of the people was a young boy with a green backpack and some sort of animal hat. Next to him was a yellow dog. A small electronic being in the shape of a box was perched nearby, and the other person was... Hunson Abadeer's daughter? They held cards in their hands, and it looked like they had been playing some sort of game before she had interrupted them.

For a few long moments, nobody moved. Then, the boy spoke.

"What are you doing in our house?"


	2. Chapter 2

**So, I realize this had taken awhile, and I'm sorry. I started writing this chapter only a few days after the story was published, but I got writer's block, and then I went to camp, and then... well, it's here now, anyway. Thanks clockwork-faerie98 and FadedBurn for reviews and faves! I don't usually write multi chapter fics, but when I do, the chapters tend to be pretty short. (Holy shit that sounded like a meme :D ) So I tried to make this longer. Enjoy!**

When Gwen didn't reply, they boy spoke again.

"Who the flip are you?" he asked.

"Um... I'm Gwendolyn. Er, Gwen, I mean, it's Gwen." She suddenly realized that she had hardly even been asked for her name in the Nightosphere.

"Why should we believe _that?_" said the boy, drawing a sword from his pack and leaping onto the table with unexpected speed. Gwen retreated.

"Chillax, guys. She's from the Nightosphere." Hunson Abadeer's daughter, who Gwen had never met but had seen in the Nightosphere from time to time, had also rose, and floated next to the boy.

This didn't seem to calm him down. In fact, it did just the opposite. He gripped his sword more tightly. "So what? do you remember what your dad did to us last time we went there?"

The dog now joined the conversation from his spot on the floor. ""Maybe she was sent by Hunson. Didn't you say demons couldn't leave the Nightosphere?"

"I didn't ask to leave the Nightosphere," Gwen explained uncertainly, noting the suspicious expressions of the boy and the dog. "There was this vortex, I didn't know what it was, so I touched it, and it took me here." She turned around, but the portal had dissapeared.

Hunson Abadeer's daughter frowned. "That's strange. Portals don't just open themselves. Finn, Jake, have you tried to get back to the Nightosphere since last time?"

"No way man, " said Jake, the dog. "That place is jank!" The other one, Finn, nodded.

Gwen shrugged. "Well, _I'm_ telling the truth."

"We should take her in for questioning at the Candy Kingdom! PB will know what to do!" Finn sheathed his sword and kicked the scattered playing cards to the side.

That didn't sound good. Gwen looked for an escape. Seeing the open window, she dashed towards it and began to climb out. Unfortunately, Jake stretched his arms further than any dog should have been able to and pulled her back. Then she was wrestled to the ground by Finn and Jake.

"Ha!" said Finn, getting up to pull out his sword again. "Now we _know_ something's up." Gwen rubbed her side, which had taken the brunt of the fall. This was just great.

Jake, who Gwen figured had some sort of magical powers, made himself into a sort of rope that tied her hands together like a prisoner's. "C'mon Marceline," said Finn as they headed out.

"Sorry about them," Marceline whispered to Gwen. "They can be a little... energetic. I'll take back home after all this is over, poor thing."

"No talking to the prisoner!" shouted Finn accusingly. Marceline rolled her eyes and chuckled.

Near the door, Gwen passed a bowl of fruit sitting on a table. It contained apples, plums, and a banana.

"Ew, nasty!" she exclaimed. "You guys keep that stuff in here?"

...

Everything outside was bright and strange. Nothing was on fire, for starters. There were plants and scenery in colors she'd rarely seen, like green and yellow. You didn't have to watch out for Mouth Worms or Tarantula Demons at all. Everything had a place, and it stayed there.

On the way to the Candy Kingdom, there were all sorts of creatures nothing like the demons she was used to. They were all different colors, instead of everyone being red or orange. They were also a lot... nicer looking. Even the mean ones. No one here kicked other people out of their way, at least. Instead, they asked nicely.

Gwen examined her own self, noticing that she didn't seem to fit in much. Lime most demons, her skin was bright red. She stood on two legs and had two arms- something she had always been grateful for, since those types of demons tended to get around better. Her rather disheveled hair was a darker red and tied in two low ponytails that hung all the way down to her lower back. Well, at least one of them did. The other one had been singed off awhile ago when she had gotten a little too close to some fire while trying to reach someone's secret burrito stash. The pigtail now reached just past her shoulder. Protruding from the top of her head were two small horns.

The walk from the house to the kingdom didn't take too long. Soon, they were nearing the edge of a bright pink place consisting of small, well kept huts centered around a sparkling palace. Little candy folk would wave and call out to Finn, or cower from Marceline. They watered their candy flowers, petted their candy dogs, and hugged their candy neighbors.

"What's wrong with these people?" muttered Gwen. She received a questioning look from Jake in his coiled rope form.

They reached the steps leading to the palace. Marceline, who was already looking uncomfortable, turned to leave.

"Oh no you don't!" Finn exclaimed. "You're staying right here."

Marceline groaned. "Why? Everyone here hates me. And I hate them," she added under her breath.

"But Marceline, you know more about the Nightosphere than anyone else. Please, Marcie? Pleeeaaaseee?" Finn begged. Jake seemed to nod in agreement, but it was hard to tell, seeing as he was coiled around Gwen's wrists.

"Fine," said the vampire. "I'll come. But expect me to get along with Princess Bubblegum."

"All right!" Finn said. He bounded up the steps into the castle.

A round peppermint candy, who was standing in the entrance hall, came to greet them.

"Finn, Jake, what can I do for you?" he said in a quavery voice.

"We'd like to see Princess Bubblegum," Finn replied. "We've got a prisoner that needs questioning!"

"Right this way," he remarked, eyed Marceline warily and paying no mind to Gwen at all. They climbed flights of stairs and hallways where no snakes jumped out at them. Gwen had to resist the urge to duck under cover from time to time. Her eyes darted around nervously, expecting an attack.

They came to a room at the top of a winding tower. Near the window stood a regal-looking girl with long pink hair and a ruffled gown. She turned to say hello and smiled.

"Hello, Finn, Jake, Marceline." She said warmly to the visitors. Gwen narrowed her eyes. "And who might this new person be?"

"She was sent here from the Nightosphere by Hunson Abadeer to kill us all!" Finn said loudly before Gwen could respond.

"I wasn't sent here by anyone," Gwen protested. "I came here by accident and was picked up by these people, who I soon found out were insane! Just let me leave, I promise I won't... blow anything up or whatever."

"Now hang on just a minute!" Jake uncoiled himself and took the shape of a dog once again. "You tried to jump out the window when we told you we were going to take you to the Candy Kingdom. What was that all about?"

The room became a flurry of argument until Princess Bubblegum interrupted. "Everyone quiet!" she demanded. They fell silent. "Now, tell me exactly what happened when this person arrived."

Finn began gladly. "We were playing Uber Cards, the most rhombus game ever-"

"You throw cards at each other until someone says "Uncle"!" Jake put in.

"Except it's way more fun," corrected Finn. "Well, Beemo had just knocked over my umbrella with the Ace of Spades, and things were looking pretty rough, until Marcie decided to step it up with a Four of Hearts..."

Gwen wandered over to the big picture window. She didn't understand the concept of games, but they seemed boring. And pointless. Especially when one is awaiting word of whether they'd get to return home or spend the rest of her life in Candy Prison. Luckily, the others didn't notice she had left the conversation, so she rested her head against the glass and tried to think clearly.

_Think, Gwen, think_, she whispered to herself. The Nightosphere Jail was a place she had ended up in once or twice, but escape was easy, seeing as half the time there was no one there to guard the cells. But this new place... was different than the Nightosphere, she realized. There was an order to it. There was structure, there were rules, and there was responsibility. Why was it so hard for her to understand? It was just so... foreign to her. That people could care about things other than themselves. But how would you know who to look out for, and who to trust? What tells you when and why to act if you had so many priorities? The idea made her head spin.

"Why can't another portal just open back up and take me home?" she wondered hopelessly. She tried to imagine one on the spotless lawn below, swirling white and electric blue like the one that had brought her here. It singed the grass and spewed dark red and purple debris into the cute little cottages. Candy people wandered out to investigate only to be knocked down by a flying brick. The perfection of the kingdom was soiled. Gwen laughed. Now this was more like it!

"Hey, what's going on out there?" Gwen stood up straight and blinked a few times as Finn and the others hurried towards the window.

"Huh?" She had completely forgotten about being under negotiation. She turned back to the window to a surprising sight. The vortex, which she had thought a mere daydream, was still there, and it looked rather destructive. Small but harmless fires had started up here and there; they seemed to be frightening the candy people, who ran blindly into each other in their panic. _Did I cause this__?_ Gwen wondered, knowing that wreaking havoc in the Candy Kingdom was a crime that did not need negotiation.

"That looks just like the portal that appeared right before _she_ showed up!" Finn exclaimed. "Except the only thing that came out of it was her, and it didn't set anything on fire."

"Is this true?" the princess said. Jake, Marceline, and Gwen nodded.

"The last time we went to the Nightosphere, there was one of those, too," Jake added helpfully. "And we landed in a pile of bananas."

"Okay..." Bubblegum began to pace. "So, aside from the fact that no one seems to be opening them, they're just regular, normal portals. Hmmm..."

Suddenly, she stopped and looked out the window. "Hold on, what am I doing? I have to go save my kingdom!" She rushed out the door, leaving the others no choice but to follow her.

...

Down on the grass, the situation wasn't any better, though the commotion had died down. The kingdom fire department had tried to put out most of the fires, but nothing could be done for the homes that had been damaged. The citizens still looked pretty confused, though.

Princess Bubblegum was nearly in tears. "You poor things!" she cried. "Let me help you."

"Oh joy, she's gone," Marceline muttered. Finn glared at the vampire.

"Come on, let's go look at that portal." He ran ahead. Gwen picked up speed. Maybe, if things went just right, she could jump into the portal. And though she wasn't sure how portals worked, there was a chance it might take her back home, if she was lucky enough. She broke into a sprint. Just a minute or two and she could leave these weirdos behind!

But when she approached the area where she had seen it, there was nothing there.

"No!" she yelled, and sunk to her knees. It was gone! And so was her hope of escape. The Nightosphere wasn't much, but it was home. When she had touched the portal that had appeared to her while she was flying through the air, Gwen hadn't considered there might be any sort of consequences. And now, there may never be another chance to get home. "Arghh! No!" She pounded the ground angrily with her fists.

Finn looked at her sympathetically. "Hey, I'm sorry," he said, kneeling down next to her. She straightened back up, puzzled.

"Why are you sorry? I thought you didn't want me to get home. I thought you wanted to put me in jail!"

"Yeah, but you're sad. I don't want anyone to be sad." He smiled at her. This time, she tried to smile back. "It looks to me like you just wanna go home."

Gwen nodded and sat down completely. "I'm never going to get back, though. I'll be stuck here forever."

"Come on, don't be like that. Another portal opened already. There's bound to be some more. And even if that doesn't work, I'm sure PB can find a way. She's smart like that."

"Really?" said Gwen. Finn nodded.

Just then, Jake and Marceline arrived. Finn and Gwen both stood up to see what they had to say.

Jake tried to catch his breath. "Princess Bubblegum decided that your interrogation can wait," he said to Gwen. "She's too busy fixing up the kingdom and stuff. But you're not allowed to leave the Candy Kingdom unless you have and escort or something. You have to stay in the jail till then."

Gwen groaned. Finn, however, shook his head. "Change of plan. You don't have to stay in the jail, Gwen. You can come with us! We can _escort_ you, and we'll teach you about not being in the Nightosphere until you can go back home!"

Jake shrugged. "Sounds fine with me, buddy. Just as long as _you_ don't try to make a break for it." He pointed accusingly at Gwen. She glared at him.

"Okay, you guys do that. I'm going to try to reach my dad," said Marceline. "He might be able to bring Gwen back, although I haven't been able to reach him lately, for whatever reason. It's worth a shot, though" She floated away.

Finn turned to Gwen. "Alright. So you're coming back home with us. But you can't be acting like you're about to do something bad all the time. That might be okay in the Nightosphere, but not everyone's gonna be okay with that here." Gwen nodded.

"So first," he said with a grin, "We're going to teach you how to be nice to people."

**Two and a half thousand words! That should be good... for now. Who's excited for the uber drama-filled new episode this Monday? I AM! Last week's episode with the Magic Man was pretty mathematical though. Well, see ya!**


End file.
